As an "old" WM I would say that this new Microsoft version of Titanium/CHome is nice. Needs some polishing but nice and functional, that will provide 'em more average Joe customers that does not like some of the features of Apple Phone and Google Phone. Let's be honest that is the goal for MS with "new" Windows Phone 7 Series.
Underneath of that "shell" there is new CE (7) that is evolutionary step from previous CE (6). Can be it be worst than CE 6 that current WM 6.5 devices are running? Don't think so. Will it bring some problems in compatibility area? Probably ... some. For android lovers I have just one area that Google will take more than few years to accomplish what MS is doing for years.
Take a look at battery capacity and Stand-by autonomy on both devices that are very similar. Another problem is open source nature of android. If open source is so great why are we all running Win7 on our rigs instead of just some of nice Linux distributions. Open Source is nice and all, but when it comes to productivity it is not, in most cases. Although I love using Linux for certain type of "jobs".
Apple Phone is ... well ... like Xbox to PC. Functional and all but not best suited for enthusiast user, but rather for one that thinks he is one (or would like to be considered as). Good as first smartphone experience for a person that is below 18 years old IMHO. I personally cannot consider Apple Phone as business solution.